Pipe & Insulation
Radial network: inner convection → cylindrical (or spherical) shell → outer convection. Includes the critical-radius-of-insulation check rcrit = k/h.
Fluids
Geometry
Frequently asked
- What is the critical radius of insulation?
- For a cylinder, r_crit = k/h. Adding insulation below r_crit increases surface area faster than it adds conduction resistance, so heat loss goes UP. The calculator shows r_crit for the outer fluid and warns when r₂ is below it.
- Cylinder vs sphere?
- Cylindrical shells use R = ln(r₂/r₁)/(2πkL); spherical shells use R = (r₂−r₁)/(4πk·r₁·r₂). Pick the shape and the areas and resistances follow.